D-optimal reliability test design for two-stress accelerated life tests

Multiple-stress accelerated life tests (ALTs) are often employed for reliability testing of electronic parts. It is important to derive the optimal designs for these tests. However, most of the existing literature on experimental design of ALTs discusses only single-stress tests. In this paper we formulate the D-optimal design for two-stress ALTs with log-normal failure time distribution. It is shown that an efficient testing plan can be obtained with required estimation precision. ALT experimental designs for both completed failure time data and time censored data are discussed.